1. Field of the Invention
The present invention relates to a fuel purifying device for use in an internal combustion engine to improve the combustion of gasoline, light oil or heavy oil used in an engine of an automobile, etc. and to purify exhausted gas.
2. Prior Art
There have been known a device for purifying fuel which is proposed by the inventor of this application and disclosed in Japanese Patent Laid-Open Publication No. 6-167254 (and corresponding U.S. Pat. No. 5,236,670) and which comprises a fuel supply pipe for use in an internal combustion engine, a fuel flowing pipe made of synthetic resin to which the fuel supply pipe is connected, a conductive coil wound around an outer periphery of the fuel flowing pipe, a protection cover for covering an outer periphery of the conductive coil. This device also has an ac signal generator connected to a battery for generating a low frequency/voltage/current signal and applying the signal to the conductive coil.
There has been also known a device for purifying fuel which is proposed by the inventor of this application and disclosed in Japanese Patent Application No. 5-257504 (and corresponding U.S. Pat. No. 5,377,648). This device comprises a fuel supply pipe for use in an internal combustion engine, a fuel flowing pipe made of synthetic resin to which the fuel supply pipe is connected, arc-shaped conductive plates which are provided in confronting relation with each other along an outer periphery of the fuel flowing pipe, a protection cover covering the outer peripheries of the conductive plates. This device also has an ac signal generator connected to a battery for generating a low frequency/voltage/current signal and applying the signal to the arc-shaped conductive plates.
However, there is little discussion of the location of the fuel purifying device in these publications, namely, a detailed location where the fuel purifying device is located on the fuel supply pipe in the aforementioned conventional devices. If the fuel purifying device is disposed only between a fuel supply pump and a fuel filter, dissolved oxygen in the fuel is increased by applying a low frequency/voltage/current signal from the fuel purifying device. However, when the dissolved oxygen reacts with metallic impurities in the fuel, colloidal cores are generated. These colloidal cores gradually and finally are caught by a fuel filter. As a result, the dissolved oxygen in the fuel is scarcely increased, which is insufficient for the improvement of the fuel.
On the other hand, if the fuel purifying device is disposed only between the fuel filter and a fuel injection pump, the dissolved oxygen in the fuel is increased by applying a low frequency/voltage/current signal from the fuel purifying device. However, the dissolved oxygen reacts on metallic impurities which are not caught by the filter, colloidal cores are generated and are is sent to an engine as it is grown up gradually, which causes incomplete combustion. As a result, an exhaust gas is polluted and the dissolved oxygen in the fuel is not so increased.